Wireless Intra-Satellite LiFi Dual CAN Bus Networks for Redundancy and Throughput

The SatelLight project focuses on the development of wireless Light Fidelity (LiFi) for nano-satellite intra-satellite communication. LiFi can provide several advantages over physical or wireless radio-spectrum based communication including a reduction in harness mass, improved reliability by removing connectors, immunity to electromagnetic interference, enhanced protection against eavesdropping, and powering of low power sensors. As part of the SatelLight project a LiFi transceiver has been developed that functions in low levels of ambient light and supports the Controller Area Network (CAN) and Universal Asynchronous Receiver Transmitter (UART) protocols. This transceiver has been shown to support communication between groups of nodes using CAN of up to 4 nodes over distances of 12 cm between each node at a baud rate of 1 Mbit s-1 and using UART at distances of up to 30 cm at baud rates of 4 Mbit s-1. However, in real world satellite bus networks, redundancy is a vital requirement for most if not all space missions. This paper presents a redundant wireless intra-satellite LiFi CAN network. The network is composed of two independent CAN physical layers transmitting on different wavelengths of light. Each physical layer is implemented as a set of LiFi transceivers where each node in the network is connected to two transceivers. This allows for the redundancy concept to be configured on the fly. The redundancy can be configured as a dual network where both networks are communicating concurrently which increases the throughput of the network. It can also be configured as a cold redundant network where only one physical layer is communicating at a time. This can also be used as a power saving method where network throughput can be reduced to conserve the power consumed by the transceivers. In addition, this can be configured on a per-node basis where high priority nodes use the dual physical layers while other nodes only use a single physical layer. The results presented in this paper show the distances and error rates are the same when only a single wavelength is transmitted or multiple wavelengths are transmitted. It also includes power measurements showing the power required for each physical layer and the trade-off between power usage and network throughput.

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600: Technology

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Wireless Intra-Satellite LiFi Dual CAN Bus Networks for Redundancy and Throughput